Sand-blast apparatus



0.' AFORSBEHG.

`SAND BLAST APPARATUS. APPLICATION FILED A1 11.16.1921.l

PandJune 13,1922.A

ZSHIEETS-SHEET 1- 0. A. FORSBERCL SAND BLAST APPARATUS.

APPLICATION FILED APR. 16" 192|.

2 SHEETS-SHEET 2.

PatentedJune 13, 1922.

(OSCAR A. FRSBERG, 0F GHICAGQ, ILLINOIS, ASSXGNOR T0 URANE COMPANY, 0F CHICGO, LLENOIS, A. CORPORATION 0F ILLNOS.

sane- BLAST Arraaarns.

Application led April le,

To all who/m, t may concern:

Be it known that l, OSCAR A. FoRsBERG, a citizen of the United States, residing at Chicago?, in the county of Cook and State of illinois, have invented certainnew and useful improvements in Sand-Blast Apparatus, of whichthe following is a speclcation.

This invention relates to sand blast apparatus for-sand-blasting bathtubs, bowls, and the like, and in fact, any cast articles which are required to be sand-blasted for the purpose ofsmoothing their surfaces prior to the enameling operations.

Prior to my invention, it has been customary in many plants to dis ose these articles in a room or chamber into which an operator enters with the sand-blast nozzle attached to a flexible'hose, and the operator directs the blast from this nozzle against the surfaces to be opera-ted upon. Vllhis operation, however, is very injurious to the health of the operator, since the dust Specification of Letters Patent. Pajtggmggd Jun@ 139 i922,

real. serial no. aerea?.

-quent delivery to the nozzles again, so that tion, compact in arrangement, and'ecient,

and fine sand particles with which the room becomes quickly filled are very injurious to the tissues of the lungs and throat, with the result that an operator is unable to continue at this work for any prolonged perio of time.

One of the primary purposes 'of my present invention is to provide a machine for performing this work, which `will be entirely automatic. in its operation, so that the artic-les are operated upon in a chamber or housing in which it is unnecessary for the operator to e ter, as the articles are automatically fed into and out ofthe cham-v ber, and the blasting operation is performed in the chamber entirely .automatically and without necessity of either manual manipu. lation or inspection within the'chamber.

Another purpose of my invention is, to provide an apparatus whlch will distribute the sand under pressure over the various surfaces of the articles to vbe operated upon, the nozzles in order to effect this result being movably mounted within the housing, and mechanism being provided which automatically moves the nozzles to VVary their direction of discharge so that all'of the surfaces of the articles are subjected to the blasting operation before the articlesare delivered from the chamber. l

Another feature of my invention resides in the fact that the sand is not only autoby my apparatus, the same sand may be repeatedly used, in the blasting operation.

A further objectrof my invention is to provide an apparatus of the character indicated, vwhich shall be simple in construcreliable and durable in operation.

For the purpose of facilitating an understandingof my invention, l have illustrated one preferred embodiment thereof on the accompanying drawings, from an inspection of which the invention and many of its inherent advantages should be kreadily understood and appreciated,A

Referring to the drawings:

Fig. 1 is a plan view of an apparatus embodying my invention; .j Fig. 2 is va longitudinal sectional view through the Yapparatus shown in Fig. l;

Fig. 3 is a fragmentary view on a large scale showing the upper nozzle mountings;

Fig. 4 is a vertical sectional view through the machine on the line 4-1-4 of Fig. 2;

Fig. 5 is an enlarged detail view of 'the lower nozzles and their mountings; and

Fig. 6 is a similar view looking toward the left-at Fig. 5.

While my apparatus may be mounted and arranged in any convenient manner and location, it is preferable for convenience in handling the articles, that the feed end of the apparatus be disposed substantially at the floor level, and the delivery end elevated somewhat above the floor level so that the articles, after'being shaken free from the molding sand, may be disposed on the apparatus without lifting, `and will be delivered from the apparatus onto trucks, by which they are transported to the enameling room, or other desired location. ln the present instance, therefore, reference character 7 indicates the door of a shop or molding room, which is provided with a pit or depression 8, in which a portion of my apparatus is disposed, so as to position the feeding or intake end 9 of the conveyor substantially level with the floor 7, thus per- `mitting thefbathtubs or other articles to be This conveyor comprises a series of side links pivotally connectedy together by transversely disposed axle rods 14, upon which are mounted the rollers 15 shaped to travell .on the tracks. These rods serve as the supports upon which the articles to be sandblasted, are carried, and since, as will be later apparent, these rods travel across the path of the blasts of sand, I found it preferable asa matter of protection to these rods,

to dispose upon each a tube or sleeve 16,

which shields the rods from the wearing action of the sand, and since the sleevesl are loosely rotatable upon the rods, the surfaces exposed to the sand blasts are continually changing, thus prolonging the life of the sleeves, as well as the rods. At the intake, or feed end of the machine, the carrier is trained over a pair of pulleys or sprocket wheels 17, and at the delivery end, similar wheels 18 are provided, this endof the conveyor being mounted upon suitable standards or supports 19 at the requisite height to deliver the articles upon trucks which are positioned at the end of the conveyor to receive the articles. The conveyor may be driven in any suitable manner, and one convenient method is to employ a drive chain 21, which is trained over a sprocket wheel fixed upon a shaft 22, upon which the carrier wheels 18 are fixedly mounted. In order to maintain the proper position of the 'con-V veyor between its sup orting end wheels, the track 12 is inclined t roughout a considerable portion of its length, asshown in Fig. 2, and the track 11 is also inclined throughout a portion of its length and suitably shaped to guide the lower lap of'the conveyor in its travel. O

The conveyor, between its ends, passes through a housing 23, which is of suitable shape, for the purposes hereinafter indicated, this housing being preferably made of sheet metal and lined with wood, orother lining which is well adapted to resist the destructive e'ects of the sand blasts. The receiving end of this housing is provided with inwardly swingingdoors or sealing iaps 24 (Fig. 1) and similarly, the delivery end is equipped with similar doors-25, which however, open outwardly so that the articles 26, shown in the present instance as bathtubs, which are moved through the housing, automatically open these sealing Haps or doors in their travel and prevent the escape of any intenso of sets of blastingnozzles, indicated generally by reference character 27. The upper portion of the housing is shaped, as shown in Fig. 2, to provide Yvertical-walls, between which theseV nozzles areounte'd, and as sho'wn in Figs). 2 and 3,-the nozzles proper are carried' by a pipe 28 mounted to' oscillate in bearings` in these walls` and aree-also e uipped -with pipes 29 which travel in s ots 31 formed in the walls. The pipes 29 areconnected by a flexible hose to an convenient source of compressed airV not shown) which may be either a compressor, or preferably,a tank, in which the requisite air pressure is. confined. The supporting pipes 28 are each connected by its respective hose 31 to the bottom of a sand hopper 32 mounted above the housing and from which sand is supplied through the hose 31 and the pipes 28 to the nozzles.

It will be apparent from Fig. 2 that the sets of nozzles'are spaced apart longitudispaced apart transversely ofthe machine,`

and all mounted to deliver downwardly and inwardly against the upper and lateral surfaces of the articles 26 disposed on the carrier. The nozzles are adapted to be oscillated about the pipe 28 as an axis-so as to vary their ldirection of discharge substantially between the positions shown in full and dotted lines respectivelyin Fig. 4, and for the purpose of effecting this oscillatory movement of the nozzles, I have'provided a constantl driven vshaft 33, which is equipped wlth a plurality of eccentrics 34 connected by links 35 to lever arms 36 fixed to the shafts 28 at one side of the machine. A downwardly depending arm 37 is con nected by a transverse connecting rod 38 with another arm 39 `fixed to the pipe 28 at the other side of the machine so that the noz zles at both sides of the machine are simultaneously operated from one eccentric 34. Both sets of nozzles disposed at different elevations, as shown in Fig. 2, are therefore operated from their respective eccentrics, with the result that the blasts of sandunder pressure are distributed over the exposed surfaces of the articles to be operated upon as these articles travel longitudinally through the housing across the paths of discharge from the various nozzles..

For the purpose of o eratingr upon the downwardly exposed sur aces of the articles which are not reached by the upper nozzles 27, I have mounted beneath the conveyor, another set of-nozzlcs 41 provided with a remise y in Figs. 5 and 6, from which it will be observed that outside the walls 46 of the hous ing, 1 have mounted supporting bearing kkes brackets 47 in which rest the depending bearing members 48 of the coupling heads 49, andv a lever 51 rigidly connecte-d with one of the coupling heads, connected by a link 52`to a bell crank lever 53 outside the housing, which in turn is actuated by'a link 54`connected with Aan eccentric 55 on the shaft 33, as shown in Fig. 2. Apertures 56 are provided in the walls 46, as shown lin Fig. 6 to permit of the oscillatory movements of the coupling heads 49 and the pipes and nozzles carried thereby.

1t will be apparent that all of the nozzles, both above and below the conveyor, are supplied With sand and with air under pressure to deliver blasts of sand against the surfaces of the articles on the conveyor, and

that all of the nozzles are oscillated back and forth within limited arcs so that the directions of the blasts delivered thereby are continuously varied, thus insuring that all of the surfaces of the articles will be reached and operated upon by the blasts. As the articles are slowly conveyed through the housing across the paths of discharge off the various nozzles, all of the surfaces, side and end, as well as top and bottom, are subjected to the action of these blasts entirely automatically and without any manual manipulation or supervision or inspection by the operator with the result that the operator is relieved of the injurious effects of the sandand dust-laden air, and furthermore,

the automatic operation is much more rapid,

efiicient and satisfactory, and produces more uniform and better results than can be secured with the customary hand manipulation of a blast nozzle.

1t willk be apparent from Fig. 4 that the conveyor rollers 15 are protected from the destructive c 'ects of the sand by inclining the walls 55 of the housing inwardly immediately above the conve or, and preferably,

a substantial seal is e ected between these walls and the lconveyor by flexible sealing strips 56. Similarly, the walls below they conveyor are inturned, as indicated at 57 and are provided at their edges with sealing strips 58, as shown. rThe lower lap of the conveyor is entirely protected from the sand by the inverted il-shaped bottom wall 59 of the housing, which divides `anddiverts laterally the lsand which descends from the upper portion of the housing, the sand being delivered through conduits 61 into downwardly'tapering passages 62 which deliver at their lower ends into elevator chambers 63, in ,which elevator belts 64,\equipped with the usual buckets, are mounted to elevate the sand from the bottom of the apparatus and return it to the hopper `32, as will be apparent from Fig. 2.

For the purpose of screening the sand and freeing it fromparticles of iron, nails and other foreign matter, the upper'ends o conduit 61 are equipped with screens 65, as

shown in kF ig. 4. For the purpose of freeing the sand from dirt, dust, and fine broken Sand particles, 1 have provided within/the housing beneath the nozzles, .downwardly i'nclined converging suction conduits 66, the

opposed ends of which have a restricted pas? sage 67 between them, through which the sand must fall. These conduits are connected the result that the sand flowing in a narrow1 sheet between the opposed ends of these conduits, is freed `from dirt and small particles so that only the clean and effective sand is returned to the hopper for future use.

It will be apparent from the foregoing that my apparatus is designed toautomatically sand-blast any articles which are loaded onto the conveyor, and that the only attention required. is in the placing ofthe articles on one end of the conveyor and the removal of them from the' opposite end. The articles during ,their `passage through the machine are thoroughly sand-blasted on ally of their surfaces, and the sand is then collected, air cleaned', screened, and then returned tothe hopper for further use. It is believed that my invention, its construction, mode of operation, and many of its advantages will be understood from the foregoing without further description, and while I have shown and described, for purposes of illustration, a preferred embodiment of the invention, obviously its details of structure may be varied within wide limits` without departing from the spirit of the'invention as defined in the following-claims.

1 claim:

1. 1n a sand blast apparatus, the combination of a chamber, an endless conveyor arranged to travel through said chamber in an upwardly inclined directioneand adapted to carry the articles to be treated, a plurality of sets of sand blast nozzles arranged in said chamber above said conveyor, a plurality of nozzles arranged in said chamber beneath the conveyor, means for oscillatin all of said nozzles so as to direct their disc arge in planes intersected b the articles on the carrier, means for supp ying sand and air under pressure to said nozzles, and doors at the ends. of the chamber adapted to normally close the chamber and to be opened bythe articles in their travel.

2. AIn a sand blast apparatus, the combina- .`tion of an enclosed sand blast chamber, a

zles, and means for collecting the discharged sand.

3. In a sand blast app aratusthe combination of a sand blast chamber, means for conveying the articles to be treated through said chamber from end to end thereof, a plurality of nozzles disposed laterally of and above the path of travel of the articles and adapted to discharge against said articles, a plurality of nozzles mounted beneath and substantially centrally of the conveyor, means .fior supplying sand and air under pressure to all of said nozzles, and means tor oscillating the nozzles so as to distribute the discharge over the surfaces of the articles.

Ll. ln a. sand blast apparatus, the combination of a sand blast chamber, a conveyor eX- tending therethrough and adapted to convey articles to be treated through said chamber, sand blast nozzles arranged above, laterally of, and beneath the conveyor to deliver` against the exposed `faces of the articles on the conveyor, mechanism for imparting an oscillatory movement to said nozzles to increase the eective area of discharge, and

means beneath the nozzles for cleaning the discharged sand and delivering it laterally of and out of contact with the lower lap of said conve or.. y

5. n a sand blast apparatus, the combination of an elongated chamber, an endless conveyor extending therethrough and adapted to convey articles to be 'treated through the chamber, a plurality of sets of nozzles mount-k ed above the conveyor, a plurality of nozzles 1,/iiaieo mounted below the conveyor, means for oscillating all of said nozzles, means .for delivering sand and air under pressure to said nozzles, means `lor cleaning the discharged sand, and means for returning'said sand to the nozzles.

6. In a sand blast apparatus, the combination of a chamber, a conveyor extending therethrough, a plurality of nozzles disposed above said conveyor, a plurality of no zles beneath saidconveyor, said last-named nozzles comprising a plurality of parallel pipes rigidly connected together and .mounted to oscillate about a common center, andmeans for oscillating all of said nozzles.

7. In a sand blast apparatus, the combination of a chamber, a plurality of pipes disposed within said chamber, nozzles attached to each of said pipes, means ttor rigidly connecting said pipes together, a pivotal support for said connecting means about which said pipes and nozzles oscillate around a common axis,'means for supplying sand and air under pressure to said pipes, and means for oscillating the pipes and nozzles carried thereby.

8. ln a'sand blast apparatus, the combination of a housing, a conveyor extending therethrough in an upwardly inclined direction, yieldable closures .for the ends` of said housing adapted to be intermittently opened by articles carried on .the conveyor, a plurality of sets of downwardly directed nozzles arran ed within said housing at different elevations to discharge against the surfaces of the articles disposed on the conveyor, a plurality of upwardly directed nozzles, means for oscillating said nozzles, and means for supplying sand and air under pressure to the nozzles.

.9. In a sand blast apparatus, the combination of a housing, a*track extending therethrough, sand blast nozzles arranged in said housing,.means for supplying sand to said nozzles and a conveyor arranged to travel on said track, said conveyor comprising transversely extending axle rods, rollers thereon,

and tubes surrounding said rods between said rollers forprotection to said rods.

OSCAR A. nonsense. 

